Cannabis Science

Does Weed Make Your Hair Grow?

woman with long blonde hair

Weed is used for many things, such as easing pain, suppressing nausea, and calming nerves. In addition to consuming weed, weed can be applied topically to achieve certain effects. For example, some creams can be applied to sore spots on the body. Nowadays, there are more and more hair care products popping up with hemp and CBD claiming to make your hair grow. Are they worth it, or is it hype?  Does weed make your hair grow? Here’s what we know. 

Photo: Unsplash

Does Weed Make Your Hair Grow Faster?

For starters, the information we have on hair products and hair growth and health is anecdotal. However, people who use hair products with cannabinoids do report healthier hair and therefore hair growth.  However, chances are weed does not make your hair grow faster but the products may help you retain length.

According to Amazon reviews for an anti breakage shampoo with hemp oil said:

“I’ve been using this shampoo only for a few weeks and I notice a significant difference in my hair. It’s the softest it’s ever been! I’m a female and my hair starting thinning after menopause. I tried everything & nothing worked…until this!”

“My hair is a lot smoother and healthier feeling now. My scalp is almost entirely bump free and itch free. And my dandruff is completely gone.”

An article in HuffPost highlighted the use of cannabidiol (CBD) in shampoos and the great results they achieve for users. But how does it work?

Dr. Jenelle Kim, the founder and lead formulator of JBK Wellness Labs says CBD interacts with the CB1 and CB2 receptors found in the area. They also spoke about the anti-inflammatory properties of CBD. Since CBD can reduce inflammation, it can help treat common scalp problems such as dandruff and eczema. Kim also mentioned that CBD can improve circulation which is essential to a healthy scalp and therefore healthy hair. 

However, according to the article, these amazing results may not be due solely to CBD. Dr. Siamak Tabib, an assistant professor of medicine at UCLA told HuffPost that hair products that use CBD have other ingredients that promote healthy hair. Tabib mentioned ingredients such as Vitamin E and macadamia nut oil. He concluded that these ingredients may give off the impression that the CBD is working even if it isn’t. 

Drawbacks of Hemp Hair Products

Even though hemp hair products may seem like a miracle product for hair and scalp problems, it may not be for you. As you know everyone reacts differently to products. Therefore, for some people, hemp infused hair products may not work. 

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A couple of reviews on Amazon under the same anti breakage shampoo with hemp oil confirms this assumption. Some reviews said:

“This hair product didn’t work for me. I didn’t have hair loss and didn’t purchase it to stop hair loss. I purchased it because it was organic and cruelty free. After using it for a few weeks I started to notice Much more hair loss than normal.”

“It just makes me no sense to me that this anti-hair loss shampoo made me lose 5X as much hair after each shower compared to when was using other shampoo. Hair loss started right after the first wash but I persisted for 2 weeks. I was losing more and more hair after each wash. I am 24 and haven’t change my lifestyle or diet while using this.”

You’ll see reviews like this under almost any hair product, even those without hemp. 

In addition to the product not working for you, or worsening your condition, you may develop an allergic reaction. The Huff Post article said all experts warned of an allergic reaction. Yes, hemp products are marked as safe for adults and kids (even though they weren’t really studied in kids). However, the possibility of an allergic reaction is present for almost any product. 

Some of the reviewers on Amazon complained about allergic reactions one said:

“Welp. I’m allergic. Within three uses, my hands and scalp are dry and cracking. My eyes swell shut after rinsing the product from my hair until my hair dries.”

Is Weed Good For Hair?

Well, we know that hemp-infused products can be great for your hair.

However, you may also be wondering about smoking weed in a bong or using it in another capacity. There is evidence that weed can actually harm hair. According to a 2007 study, the endocannabinoid seems to play a role in hair growth. The researchers found out that THC (and an endocannabinoid) stopped the hair shaft from elongating and the proliferation of hair matrix keratinocytes.

According to Di Stefano Hair Restoration Center, marijuana can increase cortisol levels which can result in hair loss. 

 A 2009 study does confirm that weed does raise your cortisol levels. The study says, “Δ-9-THC raised plasma cortisol levels in a dose-dependent manner”. In addition to that, “frequent users showed blunted increases relative to healthy controls”.

To clarify, cortisol is a stress hormone. Therefore in periods of stress, your body releases cortisol and the elevated levels can cause hair to fall out.  According to Precision Analytical Inc, one way cortisol can cause hair loss is by Telogen effluvium. That means a lot of hair is pushed into the resting phase and therefore falls out when you’re washing or combing it. 

However as Di Stefano Hair Restoration Center says, even though weed can contribute to hair loss, it’s not usually the main factor. Therefore you’ll have to find out what causes your hair loss or lack of hair growth. 

Hair Growth Tips

If you’re noticing a lot of breakage and no improvement in your hair length, there are a number of things you can try at home. 

According to Mind Body Green, some things you can do to make your hair grow longer you can:

  • Take supplements – For example, if you’re taking collagen supplements, look for cysteine, serine, glutamic acid, glycine, and proline. Biotin supplements may be helpful if you lack biotin, even though that’s probably unlikely. See your doctor before you start taking any new medication. 
  • Take care of your scalp – If your scalp is unhealthy, it will impede your goal of healthy long hair. Shampoo your hair regularly with a gentle shampoo and see a doctor for help with scalp conditions. 
  • Keep your hair moisturized – Take some time to find which moisturizers properly moisturize your hair. Remember, dry hair will get brittle and break, so moisturizing is essential. Remember to pay special attention to your ends; they’re the oldest part of your hair and the most fragile. 
  • Get rid of your split ends – Yes, you want to keep your hair length, but regularly trimming your hair can help you get longer hair in the long run. If you have split ends, as Mind Body Green says, it will split up the shaft and cause breakage. When your hair is constantly breaking, it will look like your hair isn’t growing at all. 


Does weed make your hair grow? It seems that hemp-infused hair products could promote hair growth. We’re not entirely sure that CBD is responsible for hair growth, but it does have properties that could improve scalp conditions. In addition, the other components in the hair product could also help grow the hair. There is also some evidence that THC could hinder hair growth. Remember, everyone reacts differently to marijuana, so there’s no way to know which outcome you’ll get; you’ll have to try it yourself.


About Trevann

Trevann is Stoner Rotation’s Jamaica-based lead writer for the Science section of our cannabis blog. She graduated with honors receiving her Bachelor of Science degree in Molecular Biology from the University of West Indies, Mona. For the last three years, she has covered some of the biggest questions around cannabis and health underpinned with research from supporting studies, medical journals and scholarly articles. Got something on your mind? You can reach her at [email protected].